Camera module and optical device including liquid lens

ABSTRACT

A camera module according to an embodiment includes a liquid lens unit including a cavity, a conductive liquid and a non-conductive liquid disposed in the cavity, “n” individual electrodes (n being an integer of 2 or more), and a common electrode, an interface being formed between the conductive liquid and the non-conductive liquid, a main board including an element constituting a control circuit for controlling the operation of the liquid lens unit, and a holder coupled to the main board such that the open area of an insertion hole for insertion of the liquid lens unit is disposed along a first side of the main board.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/896,659, filed Feb. 14, 2018; which is a continuation ofInternational Patent Application No. PCT/KR2017/014746, filed Dec. 14,2017; which claims priority of Korean Application No. 10-2017-0145351,filed Nov. 2, 2017; the disclosures of each of which are incorporatedherein by reference in their entirety.

TECHNICAL FIELD

Embodiments relate to a liquid lens, a camera module, and an opticaldevice. More particularly, embodiments relate to a liquid lens, thefocal length of which may be adjusted using electricity, a cameramodule, and an optical device.

BACKGROUND ART

Users of portable devices have a desire for optical devices that exhibita high resolution and a small size and have various photographingfunctions (e.g., optical zoom-in/zoom-out, auto-focusing (AF), andhandshaking correction or optical image stabilization (OIS) functions).Although these photographing functions may be implemented by combiningseveral lenses and directly moving the lenses, the size of an opticaldevice may be increased when the number of lenses is increased.

Auto-focusing and handshaking correction functions are implemented bymoving or tilting several lens modules, which are fixed to a lens holderand aligned with the optical axis, along the optical axis or in thedirection perpendicular to the optical axis, and a separate lens-drivingdevice is used to drive the lens modules. However, the lens-drivingdevice exhibits high power consumption, and a glass cover needs to beseparately added to a camera module in order to protect the lens-drivingdevice, thus causing an increase in the overall thickness.

Therefore, studies have been conducted on a liquid lens, which performsauto-focusing and handshaking correction functions by electricallyadjusting the curvature of an interface of two types of liquids.

TECHNICAL OBJECT

An object of the embodiments of the subject invention is to provide acamera module and an optical device, which include a liquid lens havingan optimum structure so as to increase camera performance.

The technical objects to be accomplished by the embodiments of thesubject invention are not limited to the aforementioned technicalobject, and other unmentioned technical objects will be clearlyunderstood from the following description by those having ordinary skillin the art.

Technical Solution

According to one embodiment,

a camera module may include a holder including a first side surfacehaving a first opening and a second side surface having a second openingthat faces the first opening in a direction perpendicular to anoptical-axis direction (e.g., perpendicular to the optical axis of alens (e.g., a liquid lens) or lens unit (e.g., a liquid lens unit) ofthe camera module), a first lens unit disposed in the holder, a secondlens unit disposed in the holder, a liquid lens unit disposed betweenthe first lens unit and the second lens unit, at least a portion of theliquid lens unit being disposed in the first opening and the secondopening in the holder, and a main board disposed below the holder, aplurality of circuit elements and an image sensor being disposed on themain board, wherein the main board includes a first long side, a secondlong side opposite the first long side, and a short side disposedbetween the first long side and the second long side so as to connectthe first long side to the second long side (the short side can have alength that is less than that of each of the first long side and thesecond long side). The first opening can be opened toward the first longside of the main board, and the second opening can be opened toward thesecond long side of the main board. That is, the holder can be arrangedsuch that a (virtual or imaginary) line extending out from the firstopening extends over the first long side of the board and a (virtual orimaginary) line extending out from the second opening extends over thesecond long side of the board.

In some embodiments, the liquid lens unit may be inserted through atleast one of the first opening and the second opening, and a portion ofthe liquid lens unit may protrude from at least one of the first sidesurface and the second side surface of the holder.

In some embodiments, the liquid lens unit may have a center thicknesssmaller than a size of the first opening in the holder with respect tothe optical-axis direction (e.g., in a direction parallel to the opticalaxis of the liquid lens unit).

In some embodiments, the circuit elements may not overlap a virtualplane, which passes through the first opening and the second opening, inthe optical-axis direction (e.g., in a direction parallel to the opticalaxis of the liquid lens unit).

In some embodiments, the liquid lens unit may include a liquid lens, andthe liquid lens may include a first plate including a cavity in which aconductive liquid and a non-conductive liquid are disposed, anindividual electrode disposed on one surface of the first plate, and acommon electrode disposed on another surface of the first plate.

In some embodiments, the liquid lens unit may further include a firstconnection substrate disposed on the liquid lens and configured toelectrically connect the common electrode and the main board to eachother, a second connection substrate disposed on the liquid lens andconfigured to electrically connect the individual electrode and the mainboard to each other, a first side surface located at the first long sideand a second side surface located at the second long side, and the firstconnection substrate may include a first bending portion, which isconnected to the common electrode, bends toward the main board, and isdisposed at a position corresponding to a center of the first sidesurface of the liquid lens unit (e.g., is lined up, in a directionperpendicular to the optical axis and parallel to an upper surface ofthe main board, with the center of the first side surface of the liquidlens unit).

In some embodiments, the second connection substrate may include asecond bending portion, which is connected to the individual electrode,bends toward the main board, and is disposed at a position correspondingto a center of the second side surface of the liquid lens unit (e.g., islined up, in a direction perpendicular to the optical axis and parallelto an upper surface of the main board, with the center of the secondside surface of the liquid lens unit).

In some embodiments, the camera module may further include a first padportion configured to be electrically connected to the first connectionsubstrate. The first pad portion can be disposed on the main board at aposition corresponding to a center of the first side surface of theliquid lens unit (e.g., lined up, in a direction perpendicular to theoptical axis and parallel to an upper surface of the main board, withthe center of the first side surface of the liquid lens unit), andextending away from the circuit elements (see, e.g., FIG. 4). Forexample, the first pad portion can include a plurality of pads, one ofwhich is closest to the circuit elements and is also disposed at aposition corresponding to the center of the first side surface of theliquid lens unit while the remaining pads are disposed at positionsextending farther away from the circuit elements (e.g., the pad that isclosest to the pad at the position corresponding to the center of thefirst side surface of the liquid lens unit is also the second-closestpad to the circuit elements, the pad closest to that pad is thethird-closest to the circuit elements, and so on).

In some embodiments, the holder may include a first hole foraccommodating the first lens unit therein and a second hole foraccommodating the second lens unit therein, the first hole and thesecond hole overlapping each other in the optical-axis direction (e.g.,in a direction parallel to the optical axis of the liquid lens unit).

In some embodiments, the camera module may further include a middle basedisposed between the holder and the main board.

In some embodiments, the camera module may further include a sensor basedisposed between the middle base and the main board, an infrared lightblocking filter being disposed on the sensor base.

In some embodiments, the middle base may include an opening into which aportion of the holder is inserted.

In some embodiments, the holder may include an upper plate, a lowerplate, and a first sidewall and a second sidewall for interconnectingthe upper plate and the lower plate, and the middle base may have athickness greater than an outer thickness of the lower plate of theholder.

In some embodiments, the camera module may further include a cover forcovering an upper surface and a side surface of the holder, the firstconnection substrate may be a metal plate, the metal plate may include alower terminal configured to be electrically connected to the main boardand an upper terminal configured to be electrically connected to theliquid lens, and the camera module may further include an insulationmaterial disposed on the metal plate in an area that faces an inner sidesurface of the cover.

In some embodiments, the insulation material may be disposed so as toextend to an area that is located below the liquid lens.

According to another embodiment, a camera module may include a holderincluding a first side surface having a first opening and a second sidesurface having a second opening, the second opening facing the firstopening in a direction perpendicular to an optical-axis direction (e.g.,perpendicular to the optical axis of a lens (e.g., a liquid lens) orlens unit (e.g., a liquid lens unit) of the camera module), a first lensunit disposed in the holder, a second lens unit disposed in the holder,a liquid lens unit disposed between the first lens unit and the secondlens unit, at least a portion of the liquid lens unit being disposed inthe first opening and the second opening in the holder, a main boarddisposed below the holder, a plurality of circuit elements and an imagesensor being disposed on the main board, and a middle base disposedbetween the liquid lens unit and the main board, a portion of the holderbeing inserted into the middle base.

In some embodiments, the camera module may further include a sensor basedisposed between the middle base and the main board, an infrared lightblocking filter being disposed on the sensor base.

In some embodiments, the middle base may have a length greater than alength of the holder in a direction from the first opening to the secondopening. According to a further embodiment, an optical device includesthe camera module, a display unit for outputting an image, a battery forsupplying power to the camera module, and a housing in which the cameramodule, the display unit, and the battery are mounted.

Aspects described above are merely some of the embodiments, and variousembodiments in which technical features of the disclosure are reflectedmay be derived and understood based on the following detaileddescription of the embodiments by those skilled in the art.

Advantageous Effects

The effects of a device according to the embodiments will be describedas follows.

With a camera module and an optical device including a liquid lens,according to an embodiment, there is no or minimal risk of damage toelements on a main board during implementation of active alignment, andsecond alignment may be appropriately completed. In addition, it ispossible to reduce the difficulty of a process of soldering eachconnection substrate to a main board and to prevent or inhibit theoccurrence of damage to elements.

In addition, by minimizing a floating or deformation phenomenon due tothe stress of an adhesive between a liquid lens and a holder, it ispossible to increase the performance of a camera module.

In addition, it is possible to enable a jig to stably perform grippingby mounting a middle base having a sufficient thickness to a holder uponthe implementation of active alignment.

The effects acquired by the embodiments are not limited to the effectsmentioned above, and other unmentioned effects will be clearlyunderstood by those skilled in the art from the following description.

DESCRIPTION OF DRAWINGS

FIG. 1 is a view for explaining an example of a camera module accordingto an embodiment of the subject invention.

FIG. 2 is an exploded view illustrating the camera module of FIG. 1.

FIG. 3 is a perspective view illustrating the camera module illustratedin FIG. 1.

FIG. 4 is a perspective view illustrating the state in which somecomponents are removed from the camera module illustrated in FIG. 3.

FIG. 5 is a cross-sectional view illustrating the camera moduleillustrated in FIG. 4.

FIG. 6 is a block diagram illustrating a camera module in brief.

FIG. 7 is a view for explaining a liquid lens, the interface of which isadjusted to correspond to a drive voltage.

FIG. 8 is a view for explaining a liquid lens of an embodiment of thesubject invention.

FIG. 9 is a top view illustrating the camera module illustrated in FIG.4.

FIG. 10 is a view illustrating a holder and a middle base in moredetail.

FIG. 11 is a view for explaining a holder and a middle base of anembodiment of the subject invention.

FIG. 12 is a view for explaining a common electrode connection substrateof an embodiment of the subject invention.

FIG. 13 is a view for explaining a liquid lens unit of an embodiment ofthe subject invention.

BEST MODE

Hereinafter, exemplary embodiments will be described in detail withreference to the accompanying drawings. The embodiments may be modifiedin various ways and may have various forms, and specific embodimentswill be illustrated in the drawings and will be described in detailherein. However, this is not intended to limit the embodiments to thespecific embodiments, and the embodiment should be understood asincluding all modifications, equivalents, and replacements that fallwithin the sprit and technical scope of the embodiments.

Although the terms “first” and “second” and the like may be used todescribe various elements, the embodiments should not be limited by theterms. These terms are used for distinguishing between similar elements.In addition, terms, which are specially defined in consideration of theconfigurations and operations of the embodiments, are given only toexplain the embodiments, and do not limit the scope of the embodiments.

In the following description of the embodiments, it will be understoodthat, when each element is referred to as being formed “on” or “under”the other element, it can be directly “on” or “under” the other elementor be indirectly formed with one or more intervening elementstherebetween. In addition, it will also be understood that “on” or“under” the element may mean an upward direction and a downwarddirection of the element.

In addition, the relative terms “top/upper/above”, “bottom/lower/under”and the like in the description and in the claims may be used todistinguish between any one substance or element and other substances orelements and not necessarily for describing any physical or logicalrelationship between the substances or elements or a particular order.

FIG. 1 is a view for explaining an example of a camera module accordingto an embodiment of the subject invention.

Referring to FIG. 1, the camera module 10 may include a lens assembly 22including a liquid lens and a plurality of lenses, a control circuit 24,and an image sensor 26.

The liquid lens may include a conductive liquid, a non-conductiveliquid, a first plate, and an electrode unit. The first plate mayinclude a cavity in which the conductive liquid and the non-conductiveliquid are accommodated. The electrode unit may be electricallyconnected to an external power supply so as to change the interface ofthe conductive liquid and the non-conductive liquid upon receiving avoltage. The liquid lens may further include an insulation layerdisposed on the electrode unit so as to inhibit an electrode from cominginto contact with the non-conductive liquid.

The camera module, to which the liquid lens is applied, may include acontroller, which controls the voltage to be applied to the electrodeunit. The electrode unit may include a first electrode and a secondelectrode, and the first electrode and the second electrode may includeat least one electrode sector. The first electrode and the secondelectrode may electromagnetically interact with each other so as tochange the interface of the conductive liquid and the non-conductiveliquid.

The lens assembly 22 may include a plurality of lenses. The lensassembly 22 may be configured with a plurality of lenses including theliquid lens, and the focal length of the liquid lens may be adjusted soas to correspond to the drive voltage applied to the first electrode andthe second electrode. The camera module 10 may further include thecontrol circuit 24 for supplying a drive voltage to the liquid lens. Thefirst electrode may be an individual electrode, and the second electrodemay be a common electrode.

The camera module 10 may include a plurality of circuits 24 and 26 thatare disposed on a single printed circuit board (PCB) and the lensassembly 22 including a plurality of lenses, but this is merely given byway of example, and the scope of the disclosure is not limited thereto.The configuration of the control circuit 24 may be designed in differentways according to the specifications required in the optical device. Inparticular, in order to reduce the magnitude of an operation voltageapplied to the lens assembly 22, the control circuit 24 may beimplemented in a single chip. Thereby, the size of an optical device,which is mounted in a portable device, may be further reduced.

The camera module 10 may be included in an optical device. The opticaldevice may include a housing in which at least one of the camera module,a display unit, a communication module, a memory storage unit, or abattery is mounted.

FIG. 2 is an exploded view illustrating the camera module 10.

Referring to FIG. 2, the camera module 10 may include a first cover 31,a first lens unit 32, a holder 33, a second lens unit 34, a middle base35, a sensor base 36, a filter 37, a second cover 38, a main board 39,and a liquid lens unit 40. According to an embodiment, at least onecomponent of the enumerated components 31 to 40 may be omitted, or atleast one other component may further be included in the camera module10.

The first cover 31 may cover a portion of the upper portion and aportion of the lateral portion of the holder 33 so as to protect thecomponents disposed therein from external shocks or external foreignsubstances. The first cover 31 may surround the first lens unit 32, theholder 33, the second lens unit 34, the middle base 35, the sensor base36, and the liquid lens unit 40, and may protect inner elements fromexternal shocks.

The first lens unit 32 may be disposed in front of the lens assembly 22,and may be an area to which light is introduced from outside the lensassembly 22. The first lens unit 32 may be configured with at least onelens, or may form an optical system in which two or more lenses arealigned along a center axis. Here, the center axis may be the same asthe optical axis of the optical system of the camera module 10. Thefirst lens unit 32 may include two lenses, without being necessarilylimited thereto.

An exposure lens (not illustrated) may be provided on the front surfaceof the first lens unit 32, and a glass cover may be disposed in front ofthe exposure lens. Since the exposure lens protrudes outward from theholder 33 and is exposed outwards, the surface thereof may be damaged.When the surface of the lens is damaged, the quality of an imagecaptured by the camera module 10 may be deteriorated. Therefore, inorder to inhibit or inhibit damage to the surface of the exposure lens,a glass cover may be disposed, or a coating layer may be formed.Alternatively, in order to inhibit damage to the surface of the exposurelens, for example, a method of forming the exposure lens using awear-resistant material having higher rigidity than the lens thatconfigures the first lens unit 32 or the second lens unit 34 may beused.

The holder 33 may include a first side surface having therein a firstopening, and a second side surface having therein a second opening,which faces the first opening in the direction perpendicular to theoptical-axis direction (e.g., perpendicular to the optical axis of alens (e.g., a liquid lens) or lens unit (e.g., a liquid lens unit) ofthe camera module). The holder 33 may be open at the top and the bottomthereof so as to include a through-hole, and the first lens unit 32, thesecond lens unit 34, and the liquid lens unit 40 may be disposed in thethrough-hole formed in the holder 33. In addition, the first lens unit32 and the second lens unit 34 may be defined as a first solid lens unitand a second solid lens unit to distinguish the same from the liquidlens unit 40. Specifically, the first lens unit 32 may be disposed inand coupled into a first hole, which is formed in the top of the holder33, and the second lens unit 34 may be disposed in and coupled into asecond hole, which is formed in the bottom of the holder 33. Inaddition, the liquid lens unit 40 may be disposed in and coupled intothe first opening and/or the second opening, which are located betweenthe first hole and the second hole. In addition, the liquid lens unit 40may be located between the first hole and the second hole, and may bedisposed in the space between the first opening and the second opening.

The second lens unit 34 may be disposed below the first lens unit 32 andthe liquid lens unit 40, and light introduced into the first lens unit32 from outside the camera module 10 may pass through the liquid lensunit 40 and be introduced into the second lens unit 34. The second lensunit 34 may be spaced apart from the first lens unit 32 and may bedisposed in the second hole formed in the holder 33.

The middle base 35 may be disposed below the holder 33. The middle base35 may be disposed and coupled so as to surround the second hole in theholder 33. The middle base 35 may include an accommodating hole foraccommodating therein the second hole. The middle base 35 may include anopening into which a portion of the holder is inserted. Thus, the innerdiameter of the middle base 35 (i.e. the diameter of the accommodatinghole or the opening) may be equal to or greater than the outer diameterof the second hole. Here, each of the accommodating hole in the middlebase 35 and the second through-hole is illustrated as having a circularshape, but the scope of the disclosure is not limited thereto, and theseholes may be changed to various other shapes.

The sensor base 36 may be disposed below the middle base 35 and may bebonded to the main board 39. The sensor base 36 may surround an imagesensor 50 and may protect the image sensor 50 from external foreignsubstances or shocks.

The filter 37 may filter light corresponding to a specific wavelengthrange from the light that has passed through the first lens unit 32, theliquid lens unit 40, and the second lens unit 34. The filter 37 may bean infrared (IR) cutoff filter or an ultraviolet (UV) cut filter, butthe scope of the disclosure is not limited thereto. The filter 37 may bedisposed above the image sensor. The filter 37 may be disposed insidethe sensor base 36. The filter 37 may be disposed or mounted in an innerrecess in the sensor base 36 or on a stepped portion thereof.

The second cover 38 may be mounted on the top of the main board 39, andmay protect the components 31 to 37 as well as an element 51 on the mainboard 39 from external shocks or foreign substances. To this end, thesecond cover 38 may include a space for accommodating the element 51therein, which is formed in consideration of the shape and position ofthe element 51, and a space for accommodating the lens assembly 22therein, which is formed in consideration of the shape and position ofthe lens assembly 22 coupled to the components 31 to 37.

The main board 39 may be disposed below the sensor base 36, and mayinclude a recess, in which the image sensor 50 is accommodated, theelement 51, a flexible printed circuit board (FPCB) 52, and a connector53.

The image sensor 50 may be mounted in a recess formed in the main board39, and may perform a function of converting the light that has passedthrough the lens assembly 22 into image data. More specifically, theimage sensor 50 may convert light into analog signals via a pixel arrayincluding a plurality of pixels, and may generate image data bysynthesizing digital signals corresponding to the analog signals.

The main board 39 and the element 51 may constitute a module (e.g. acontrol circuit in FIG. 6), which controls the liquid lens unit 40 andthe image sensor 50. The element 51 may include at least one of apassive element or an active element, and may have any of various widthsand heights. That is, the element 51 may mean a plurality of circuitelements, and may have a height greater than the height of the mainboard 39 so as to protrude outward. The plurality of circuit elementsmay represent elements that do not overlap the holder in the directionparallel to the optical axis. In addition, the main board 39 may includea first area in which the holder is disposed and a second area in whichthe plurality of circuit elements is disposed.

The main board 39 may be configured as a rigid flexible printed circuitboard (RFPCB) including the FPCB 52. The FPCB 52 may bend depending onthe requirement of the space in which the camera module 10 is mounted.

The connector 53 may electrically connect the main board 39 to a powersupply or any other device (e.g. an application processor) outside thecamera module 10.

The liquid lens unit 40 may be inserted into an insertion hole formedbetween the first through-hole and the second through-hole in the holder33. The liquid lens unit 40 may be inserted into or disposed in thefirst opening and/or the second opening, which are formed in thesidewalls of the holder. The liquid lens unit 40 may include a liquidlens 42. The liquid lens unit 40 may have a structure in whichconnection substrates 41 and 44 or a spacer 43 are connected to theliquid lens 42. In addition, the liquid lens unit 40 may have astructure in which the connection substrates 41 and 44 and the spacer 43are connected to the liquid lens 42. In an embodiment, the liquid lensunit 40 may include an individual electrode connection substrate 41, theliquid lens 42, the spacer 43, and a common electrode connectionsubstrate 44, but at least one of the spacer 43 or the connectionsubstrates 43 and 44 may be omitted.

The individual electrode connection substrate 41 may electricallyconnect an individual electrode of the liquid lens unit 40 to the mainboard 39. The individual electrode connection substrate 41 may beimplemented into an FPCB. The individual electrode connection substrate41 may be defined as a second connection substrate. The liquid lens 42may include a plurality of plates formed so as to accommodate twodifferent types of liquids.

The spacer 43 may be coupled so as to surround the liquid lens 42, andmay protect the liquid lens 42 from external shocks. The spacer 43 maybe disposed in a ring shape so as to surround the side surface of theliquid lens 42. The spacer 43 may be disposed between the firstconnection substrate and the second connection substrate. The spacer 43may be disposed in the opening in the holder 33. In addition, the spacer43 may be disposed so as to protrude outward through the opening in theholder 33. The upper surface or the lower surface of the spacer 43 maybe provided with an uneven portion. When an adhesive is applied to theuneven portion, the spacer may achieve increased adhesive coupling forcewith the connection substrates. In addition, the spacer 43 may bebrought into contact with a gripper when inserted into the holder 33 orduring active alignment.

The common electrode connection substrate 44 may electrically connectthe common electrode of the liquid lens unit 40 to the main board 39.The common electrode connection substrate 44 may be implemented as aflexible printed circuit board (FPCB) or a single metal substrate(conductive metal plate), and may be implemented as a metal plateincluding an insulation layer provided in at least a portion thereofexcluding an exposed pad at a position corresponding to the commonelectrode of the liquid lens 42 and an exposed pad at a positioncorresponding to a common electrode pad of the main board 39. Thisstructure will be described later with reference to FIGS. 12 and 13. Thecommon electrode connection substrate 44 may be defined as the firstconnection substrate.

Each of the connection substrates 41 and 44 may have a shapecorresponding to the shape of the spacer 43, and may include an areathat overlaps the spacer 43, and an area that overlaps the electrode ofthe liquid lens 42, in the direction parallel to the optical axis. Thearea that overlaps the electrode may be formed so as to protrude orextend inward from the inner circumference of the area that overlaps thespacer 43.

FIG. 3 is a perspective view illustrating the camera module illustratedin FIG. 1.

Referring to FIG. 3, the first cover 31 included in the camera module 10may be disposed so as to effectively protect a plurality of lensesconstituting an optical system from external shocks.

The second cover 38 may protect the element 51 on the top of the mainboard 39, and may accommodate and protect the first cover 31 therein.

FIG. 4 is a perspective view illustrating the state in which somecomponents are removed from the camera module illustrated in FIG. 3.

Referring to FIG. 4, a camera module 10-1 in the state in which thefirst cover 31 and the second cover 38 are removed from the cameramodule 10 is illustrated.

The sensor base 36 may be mounted on the main board 39 so as to bespaced apart from the element 51. The holder 33 in which the middle base35, the second lens unit 34, the liquid lens unit 40, and the first lensunit 32 are disposed may be disposed above the sensor base 36.

Each of the common electrode connection substrate 44 and the individualelectrode connection substrate 41 may bend toward the main board 39. Theindividual electrode connection substrate 41 may be electricallyconnected to an electrode pad 55, which is formed on the main board 39,via a connection pad 54, which is electrically connected to respectiveindividual electrodes. The connection pad 54 and the electrode pad 55may be electrically connected to each other using conductive epoxy or bysoldering, but the scope of the disclosure is not limited thereto.

In the same manner, the common electrode connection substrate 44 may beelectrically connected to an electrode pad, which is formed on the mainboard 39, via a connection pad, which is electrically connected to thecommon electrode.

Here, the electrode pads, which are connected to the common electrodeconnection substrate 44 and the individual electrode connectionsubstrate 41, may be respectively defined as a first pad portion and asecond pad portion, and each of the first pad portion and the second padportion may be disposed in a direction from the center of the liquidlens (the first side surface or the second side surface, which will bedescribed in FIG. 10) to be opposite the element 51 disposed on the mainboard 39.

FIG. 5 is a cross-sectional view illustrating the camera moduleillustrated in FIG. 4.

Referring to FIG. 5, the illustrated cross-sectional structure (thecross section taken along line A-A′ of FIG. 4) of the camera module 10-1is merely given by way of example, and the structure of the cameramodule 10-1 may be changed according to the specifications required ofan optical device. For example, the liquid lens unit 40 is locatedbetween the first lens unit 32 and the second lens unit 34 in theillustrated example, but the first lens unit 32 or the second lens unitmay be omitted in another example. In addition, the liquid lens unit 40may be located above (on the front surface of) the first lens unit 32,or the liquid lens unit 40 may be located below the second lens unit 34.

The liquid lens unit 40 includes a cavity 310 defined by an open area.In another example, the liquid lens unit 40 may be disposed such thatthe direction of inclination of the cavity 310 is opposite that of theliquid lens unit. This may mean that, unlike FIG. 5, the open area inthe direction in which light is introduced into the cavity 310 issmaller than the open area in the opposite direction. That is, the openarea of the cavity 310 may be determined such that the open area in thelight introduction direction is smaller or greater than the open area inthe opposite direction. When the liquid lens unit 40 is disposed so thatthe direction of inclination of the cavity 310 is opposite to that ofthe liquid lens unit, depending on the direction of inclination of theliquid lens unit 40, a part or the entirety of the arrangement ofcomponents of the liquid lens unit such as the electrode and the liquidsmay be changed, or only the direction of inclination of the cavity maybe changed and the remainder of the arrangement may not be changed. Thatis, the vertical positions of the respective components of the liquidlens unit 40 may be changed.

The liquid lens unit 40 may include the cavity 310. The cavity 310 is aregion through which the light that has passed through the first lensunit 32 passes, and may include a liquid in at least a portion thereof.For example, two types of liquids, i.e. a conductive liquid and anon-conductive liquid (or insulative liquid) may be included together inthe cavity 310, and the conductive liquid and the non-conductive liquidmay not be mixed with each other, but an interface may be formed betweenthe conductive liquid and the non-conductive liquid. The interfacebetween the conductive liquid and the non-conductive liquid may bedeformed by a drive voltage applied via the common electrode connectionsubstrate 44 and the individual electrode connection substrate 41, suchthat the curvature and/or the focal length of the liquid lens unit 40may be changed. When the deformation and the change in curvature of theinterface are controlled, the liquid lens unit 40, the lens assembly 22,the camera module 10, and the optical device including the same mayperform an auto-focusing (AF) function, a handshaking correctionfunction, an optical image stabilization (OIS) function, or the like.

As described above, the holder 33 may include the first through-hole (orthe first hole), in which the first lens unit 32 is disposed, theinsertion hole, in which the liquid lens unit 40 is disposed, and thesecond through-hole (or the second hole) in which the second lens unit34 is disposed. The first hole and the second hole may overlap eachother in the optical-axis direction.

The first lens unit 32 may include two lenses and the second lens unit34 may include three lenses, but this is merely given by way of example,and the number of lenses included in the respective lens units 32 and 34may be changed. Meanwhile, a lens located on the top of the first lensunit 32 may protrude upward so as to perform a function of the exposurelens. In addition, the outer diameters of the lenses included in thelens units 32 and 34 may increase downward, but the scope of thedisclosure is not limited thereto.

The optical axis may be the optical axis of the image sensor 50, and mayalso be the optical axis of the optical system formed by the first lensunit 32, the liquid lens unit 40, and the second lens unit 34. That is,the image sensor 50, the first lens unit 32, the liquid lens unit 40,and the second lens unit 34 may be disposed so as to be aligned along asingle optical axis via active alignment.

Here, active alignment may mean an operation of aligning the opticalaxis of each of the first lens unit 32, the second lens unit 34, and theliquid lens unit 40 with the optical axis of the image sensor 50. In anembodiment, active alignment may be performed by an operation in whichthe image sensor 50 generates and analyzes image data when receivinglight introduced from a specific object via at least one of the firstlens unit 32, the second lens unit 34, or the liquid lens unit 40.

Although active alignment may be performed in various sequences, in thisspecification, it is assumed that first alignment between the first andsecond lens units 32 and 34 fixed and mounted to the holder 33 and theimage sensor 50 is completed, and thereafter second alignment betweenthe liquid lens unit 40 inserted into the holder and the image sensor 50is performed. First alignment may be performed as a gripper grips themiddle base 35 mounted to the holder 33 and displaces the middle base tovarious positions, and second alignment may be performed as the grippergrips the spacer 43 of the liquid lens unit 40 and displacers the spacerto various positions. This is merely given as an embodiment, and activealignment may be performed in any other order.

Each of the respective components 31 to 40 described in FIGS. 1 to 5 maybe fixed and bonded to each other using epoxy. To this end, whenattempting to fix and bond two components among the components 31 to 40,epoxy application, UV curing, and thermal curing may be sequentiallyperformed. In some embodiments, any one curing process may be omittedaccording to the material or characteristics of the components, andanother bonding process may be added.

FIG. 6 is a block diagram illustrating a camera module in brief.

Referring to FIG. 6, a control circuit 210 and a lens assembly 250included in the camera module 200 are illustrated, and the controlcircuit 210 and the lens assembly 250 may correspond to the controlcircuit 24 and the lens assembly 22 of FIG. 1, respectively.

The control circuit 210 may include a control unit 220.

The control unit 220 is a component for performing an AF function and anOIS function, and may control a liquid lens module 260 included in thelens assembly 250 using a user request or a sensed result (e.g. amovement signal of a gyro sensor 225).

The control unit 220 may include a controller 230 and a voltage driver235. The gyro sensor 225 may be an independent component, which is notincluded in the control unit 220, or the control unit 220 may furtherinclude the gyro sensor 225.

The gyro sensor 225 may sense the angular speed of a movement in twodirections, including a yaw axis and a pitch axis, in order tocompensate for (or, correct) handshaking in the horizontal and verticaldirections of an optical device. The gyro sensor 225 may generate amovement signal corresponding to the sensed angular speed and providethe signal to the controller 230.

The controller 230 may remove a high frequency noise component from themovement signal using a low-pass filter (LPF) so as to extract only adesired frequency band for the implementation of an OIS function, maycalculate the amount of handshaking using the movement signal from whichthe noise component has been removed, and may calculate a drive voltagecorresponding to the shape that a liquid lens 280 of the liquid lensmodule 260 needs to have in order to compensate for the calculatedamount of handshaking.

The controller 230 may receive information for an AF function (i.e.information on the distance to an object) from an internal component(e.g. an image sensor) or an external component (e.g. a distance sensoror an application processor) of the camera module 200 or the opticaldevice, and may calculate the drive voltage corresponding to the desiredshape of the liquid lens 280 based on a focal length, which is requiredto focus on the object, using the distance information.

The controller 230 may store a drive voltage table in which a drivevoltage and a drive voltage code for making the voltage driver 235generate the drive voltage are mapped, and may acquire the drive voltagecode corresponding to the calculated drive voltage by referring to thedrive voltage table.

The voltage driver 235 may generate a drive voltage in an analog form,which corresponds to the drive voltage code, based on a drive voltagecode in a digital form provided from the controller 230, and may providethe drive voltage to the lens assembly 250.

The voltage driver 235 may include a voltage booster, which increases avoltage level upon receiving a supply voltage (e.g. a voltage suppliedfrom a separate power supply circuit), a voltage stabilizer forstabilizing the output of the voltage booster, and a switching unit forselectively supplying the output of the voltage booster to each terminalof the liquid lens 280.

Here, the switching unit may include a circuit component called an Hbridge. A high voltage output from the voltage booster is applied as apower supply voltage of the switching unit. The switching unit mayselectively supply the applied power supply voltage and a ground voltageto opposite ends of the liquid lens 280. Here, the liquid lens 280 mayinclude a first electrode including four electrode sectors and a secondelectrode including one electrode sensor for driving. Opposite ends ofthe liquid lens 280 may mean the first electrode and the secondelectrode. In addition, opposite ends of the liquid lens 280 may meanany one of the four electrode sectors of the first electrode and oneelectrode sector of the second electrode.

A pulse-type voltage having a predetermined width may be applied to eachelectrode sector of the liquid lens 280, and the drive voltage appliedto the liquid lens 280 is the difference between the voltages appliedrespectively to the first electrode and the second electrode. Here, thevoltage applied to respective electrode sectors of the first electrodemay be defined as an individual voltage, and the voltage applied to theelectrode sector of the second electrode may be defined as a commonvoltage.

That is, in order to allow the voltage driver 235 to control a drivevoltage applied to the liquid lens 280 depending on a drive voltage codein a digital form provided from the controller 230, the voltage boostermay control an increase in a voltage level, and the switching unit maycontrol the phase of a pulse voltage applied to a common electrode andan individual electrode so as to generate a drive voltage in an analogform, which corresponds to the drive voltage code.

That is, the control unit 220 may control the voltage applied to each ofthe first electrode and the second electrode.

The control circuit 210 may further include a connector (notillustrated), which performs a communication or interface function ofthe control circuit 210. For example, the connector may performcommunication protocol conversion for communication between the controlcircuit 210, which uses an inter-integrated circuit (I²C) communicationmethod, and the lens assembly 250, which uses a mobile industryprocessor interface (MIPI) communication method.

In addition, the connector may receive power from an external source(e.g. a battery), and may supply power required for the operation of thecontrol unit 220 and the lens assembly 250. In this case, the connectormay be the same as the connector 53 of FIG. 2.

The lens assembly 250 may include the liquid lens module 260, and theliquid lens module 260 may include a drive voltage provider 270 and theliquid lens 280.

The drive voltage provider 270 may receive a drive voltage (i.e. ananalog voltage applied between one common electrode and any oneindividual electrode among “n” individual electrodes, (“n” being aninteger of 2 or more)) from the voltage driver 235, and may provide thedrive voltage to the liquid lens 280. The drive voltage provider 270 mayinclude a voltage adjustment circuit or a noise removal circuit forcompensating for loss due to terminal connection between the controlcircuit 210 and the lens assembly 250, or may bypass the output voltage.

The drive voltage provider 270 may be disposed on a flexible printedcircuit board (FPCB) or a first substrate, which constitutes at least aportion of a connector 53 of FIG. 2, but the scope of the disclosure isnot limited thereto. The connector 53 may include the drive voltageprovider 270.

The liquid lens 280 may perform an AF function or an OIS functionthrough the deforming of the interface between a conductive liquid and anon-conductive liquid depending on a drive voltage.

FIG. 7 is a view for explaining a liquid lens, the interface of which isadjusted to correspond to a drive voltage. Specifically, (a) explains aliquid lens 28 included in the lens assembly 22, and (b) explains anequivalent circuit of the liquid lens 28. Here, the liquid lens 28 isthe same as the liquid lens 42 of FIG. 2.

Referring first to (a), the liquid lens 28, the interface of which isadjusted to correspond to a drive voltage, may receive the drive voltagevia a plurality of electrode sectors L1, L2, L3 and L4, which aredisposed in four different directions to have the same angular distancetherebetween and constitute a first electrode, and an electrode sectorCO of a second electrode. When the drive voltage is applied via theplurality of electrode sectors L1, L2, L3 and L4, which constitute thefirst electrode, and the electrode sector CO, which constitutes thesecond electrode, the interface between the conductive liquid and thenon-conductive liquid, which are accommodated in the cavity 310, may bedeformed. The degree of deformation and the shape of the interfacebetween the conductive liquid and the non-conductive liquid may becontrolled by the controller 230 in order to implement an AF function oran OIS function.

In addition, referring to (b), the lens 28 may be explained as aplurality of capacitors 29 in which one side of the lens 28 receives avoltage from the different electrode sectors L1, L2, L3 and L4 of thefirst electrode, and the other side is connected to the electrode sectorCO of the second electrode so as to receive a voltage therefrom.

The number of different electrode sectors has been described as beingfour in this specification by way of example, but the scope of thedisclosure is not limited thereto.

FIG. 8 is a view for explaining an embodiment of the liquid lens.Specifically, (a) in FIG. 8 is a top view illustrating the embodiment ofthe liquid lens, and (b) in FIG. 8 is a cross-sectional viewillustrating the embodiment of the liquid lens.

Referring to FIG. 8, the liquid lens 28 may include two different typesof liquids, a first plate 81, and electrodes. The two liquids 82 and 83included in the liquid lens may include a conductive liquid and anon-conductive liquid. The first plate 81 may include a cavity 85 inwhich the conductive liquid and the non-conductive liquid areaccommodated. The sidewall surface of the cavity 85 may include aninclined surface. The electrodes may be disposed on the first plate 81,and may be disposed on the top of the first plate 81 or the bottom ofthe first plate 81. The liquid lens 28 may further include a secondplate 86, which may be disposed above (below) the electrodes. Inaddition, the liquid lens may further include a third plate 87, whichmay be disposed below (above) the electrodes. As illustrated, in oneembodiment, the liquid lens 28 may include an interface 84 defined bythe two different types of liquids 82 and 83. In addition, one or moresubstrates 91 and 92 may be included to supply a voltage to the liquidlens 28. Here, the substrates 91 and 92 may respectively mean the commonelectrode connection substrate 44 and the individual electrodeconnection substrate 41. The corners of the liquid lens 28 may bethinner than the center portion of the liquid lens 28. The corners ofthe second plate or the third plate may be partially removed so thatportions of the electrodes disposed on the first plate are exposed.

The liquid lens 28 may include two different types of liquids, forexample, the conductive liquid 83 and the non-conductive liquid 82, andthe curvature and shape of the interface 84 defined by the two differenttypes of liquids may be adjusted by a drive voltage supplied to theliquid lens 28. The drive voltage supplied to the liquid lens 28 may betransferred via the first substrate 92 and the second substrate 91. Thefirst substrate 92 may transfer four individual drive voltages, whichare distinguished from each other, and the second substrate 91 maytransfer a single common voltage. The common voltage may include a DCvoltage or an AC voltage. When the common voltage is applied in a pulseform, the pulse width or the duty cycle may be consistent. The voltagesupplied via the second substrate 91 and the first substrate 92 may beapplied to a plurality of electrodes 88 and 89, which are exposed on therespective corners of the liquid lens 28. Conductive epoxy may bedisposed between the electrodes and the substrates, and the electrodesand the substrates may be coupled to each other in an electricalconduction manner via the conductive epoxy.

In addition, the liquid lens 28 may include the first plate 81, which islocated between the third plate 87 and the second plate 86, both ofwhich include a transparent material. The first plate includes an openarea defined by a surface having a predetermined inclination.

The second plate 86 may have a square shape having a first width D1. Thesecond plate 86 may be bonded to the first plate 81 by being in contactat the bonding area around the edge with the first plate, and the firstplate 81 may have an inclined surface and a diameter D3 of a wide openarea 48 may be smaller than the diameter D2 of a peripheral area 46. Theperipheral area 46 may overlap the upper surface of the first plate 81and the liquids in the vertical direction or in the direction parallelto the optical axis. A portion of the first electrode 88 disposed on thefirst plate 81 may be exposed so that a portion of the electrode patternformed on the first plate 81 may be exposed to the conductive liquid. Insome embodiments, the second plate 86 may have a diameter D2 greaterthan the diameter D3 of the wide open area in the first plate 81.

In addition, the liquid lens 28 may include the cavity 85 defined by thethird plate 87, the second plate 86, and the open area in the firstplate 81. Here, the cavity 85 may be filled with the two different typesof liquids 82 and 83 (e.g. the conductive liquid and the non-conductiveliquid), and the interface 84 may be formed between the two differenttypes of liquids 82 and 83.

In addition, at least one of the two liquids 82 and 83 included in theliquid lens 28 may be conductive, and the liquid lens 28 may furtherinclude an insulation layer 90 disposed on the inclined surface at whichthe two electrodes 88 and 89 disposed above and below the first plate 81may be in contact with the conductive liquid. The insulation layer 90may be disposed between the inner inclined surface of the first plate 81and the liquids 82 and 83. Here, the insulation layer 90 may cover oneelectrode (e.g. the second electrode 89) among the two electrodes 88 and89, and may expose a portion of the other electrode (e.g. the firstelectrode 88) so that electricity is applied to the conductive liquid(e.g. 83). Here, the first electrode 88 may include at least oneelectrode sector, and the second electrode 89 may include two or moreelectrode sectors. For example, the second electrode 89 may include aplurality of electrode sectors sequentially disposed in the clockwisedirection about the optical axis.

One or two or more substrates 91 and 92 may be connected to transfer adrive voltage to the two electrodes 88 and 89 included in the liquidlens 28. The focal length of the liquid lens 28 may be adjusted as theflexion, inclination, or the like of the interface 84 formed in theliquid lens 28 is changed to correspond to the drive voltage.

Meanwhile, the first plate 81 may include the open area, and the openarea may include a wide open area and a narrow open area defined by theinner inclined surface of the first plate 81. The diameter D3 of thewide open area may be changed depending on the field of view (FOV)required for the liquid lens or the role of the liquid lens in a cameradevice. The open area may take the form of a hole having a circularcross section, and the inclined surface of the open area may have aninclination angle ranging from 55 degrees to 65 degrees. The interface84 formed by the two liquids may be moved along the inclined surface ofthe open area by the drive voltage.

FIG. 9 is a top view illustrating the camera module illustrated in FIG.4.

Referring to FIG. 9, the camera module 10-1 may be divided into an areain which the lens assembly 22 is disposed, an area in which the element51 is disposed, the FPCB 52, and the connector 53. In addition, unlikeFIG. 4, FIG. 9 illustrates the state in which the common electrodeconnection substrate 44 and the individual electrode connectionsubstrate 41 are not subjected to bending.

In FIG. 9, the direction parallel to the long side (or the first side)of the main board 39 having a rectangular shape is defined as a firstdirection DR1, and the direction parallel to the short side (or thesecond side) of the main board 39 is defined as a second direction DR2.The respective sides of the main board 39 may be uneven.

In addition, the long side may conceptually include a first long sidelocated at the upper side and a second long side located at the lowerside, and the short side may be disposed between the first long side andthe second long side or may interconnect the first long side and thesecond long side.

According to an embodiment of a method of manufacturing the cameramodule 10-1, the image sensor 50 may be mounted on the main board 39,and the sensor base 36 coupled to the filter 37 may be coupled to themain board 39.

Thereafter, active alignment (first alignment) may be performed toadjust relative positions between the first lens unit 32 and the secondlens unit 34, which are disposed in the holder 33 coupled to the middlebase 35, and the image sensor 50 disposed on the main board 39. Firstalignment may be performed by adjusting the positions of the middle base35 and the holder coupled to the middle base 35 while supportingopposite sides of the middle base 35. First alignment may be performedwhile moving a jig, which presses and fixes opposite sides of the middlebase 35. The middle base 35 and the sensor base 36 may be coupled toeach other in the state in which first alignment is completed.

Thereafter, the liquid lens unit 40 may be inserted into the insertionhole in the holder 33, and active alignment (second alignment) betweenthe liquid lens unit 40 and the image sensor 50 may be performed. Secondalignment may be performed by adjusting the position of the liquid lensunit 40 while supporting the liquid lens unit 40 in the second directionDR2. Second alignment may be performed by adjusting the position of theliquid lens unit 40 while supporting the spacer 43 of the liquid lensunit 40 in the second direction DR2. Second alignment may be performedwhile moving a jig, which presses and fixes the liquid lens unit 40 inthe second direction DR2.

At this time, in the case where the open area of the insertion hole inthe holder 33 is disposed along the short side of the main board 39 andsecond alignment needs to be performed while moving a jig, which pressesand fixes the liquid lens unit 40, in the first direction DR1, there isa risk of the element 51 included in the main board 39 being damaged dueto movement of the jig. In addition, when the movement of the jig islimited in order to inhibit damage to the element 51, second alignmentmay not be appropriately completed and the performance of the cameramodule 10-1 may be greatly deteriorated. In addition, a solderingprocess is required in order to electrically connect the respectiveconnection substrates 41 and 44 to the main board 39 after a bendingprocess. In this case, a pad of the main board 39 connected to any oneof the connection substrates 41 and 44 becomes close to the element 51,which may cause damage to the element 51, and the difficulty of thesoldering process may be increased.

However, with the camera module 10-1 according to the embodiment, sincethe open area of the insertion hole in the holder 33, which is coupledto the main board 39, is disposed along the long side of the main board39 (alternatively, a virtual straight line, which passes through theopen area in the insertion hole in the direction parallel to the shortside, does not overlap the element 51), second alignment may beperformed while moving a jig, which presses and fixes the liquid lensunit 40, in the second direction DR2. That is, since the movement rangeof the jig may not overlap the area in which the element 51 is located,there is no risk of damage to the element 51 and second alignment may beappropriately completed. In addition, the difficulty of the process ofsoldering the respective connection substrates 41 and 44 to the mainboard 39 may be reduced and the occurrence of damage to the element 51may be inhibited.

In the state in which second alignment is completed, the holder 33 andthe liquid lens unit 40 may be bonded and fixed to each other via abonding process (e.g. an epoxy application and curing process). Afterthe bonding process is completed, each of a first bending area 64 (or afirst bending portion) of the common electrode connection substrate 44and a second bending area 61 (or the second bending portion) of theindividual electrode connection substrate 41 may be subjected to abending process. The bending process means a process of folding therespective substrates 41 and 44 toward the main board 39 along apredetermined bending line. The connection substrates may include agroove 45 in the bending portion thereof for easy bending. The bendingline may be included in each of the first bending area 64 or the secondbending area 61. The length of each of the first bending area 64 and thesecond bending area 61 may be experimentally predetermined for easybending.

As illustrated in FIG. 9, the first bending area 64 may be disposedclose to the center of an exposed side 74 of the common electrodeconnection substrate 44 and the second bending area 61 may be disposedclose to the center of an exposed side 71 of the individual electrodeconnection substrate 41. For example, the center of the exposed side 74and the center of the exposed side 71 may be included respectively inthe first bending area 64 and the second bending area 61. According toanother embodiment, any one of the center of the exposed side 74 and thecenter of the exposed side 71 may be included in a corresponding one ofthe first bending area 64 and the second bending area 61.

Alternatively, even if any one of the center of the exposed side 74 andthe center of the exposed side 71 is not included in a corresponding oneof the first bending area 64 and the second bending area 61, the firstbending area 64 may be disposed as close as possible to the center ofthe exposed side 74 of the common electrode connection substrate 44, andthe second bending area 61 may be disposed as close as possible to thecenter of the exposed side 71 of the individual electrode connectionsubstrate 41.

Upon the implementation of the bending process, a floating ordeformation phenomenon may occur due to the stress of epoxy, which fixesthe holder 33 and the liquid lens unit 40 to each other. This phenomenonmay cause a change in the position of the liquid lens unit 40 determinedby second alignment, thereby greatly deteriorating the performance ofthe camera module 10-1. As the first bending area 64 and the secondbending area 61 are located respectively closer to the edges of theexposed side 74 of the common electrode connection substrate 44 and theexposed side 71 of the individual electrode connection substrate 41, thefloating or deformation phenomenon due to the stress of epoxy may beworsened.

Thus, with the camera module 10-1 according to the embodiment, theperformance of the camera module 10-1 may be increased by minimizing afloating or deformation phenomenon due to the stress of an adhesivebetween the liquid lens unit 40 and the holder 33.

In addition, as illustrated in FIG. 9, pads, which are provided on themain board 39 for electrical connection with the respective connectionsubstrates 41 and 44, may be disposed farthest from the element 51 (ordeviated from the center of the respective exposed sides 71 and 74 inthe direction opposite the element 51), thereby minimizing a negativeeffect on the element 51 during the soldering process.

FIG. 10 is a first perspective view illustrating the holder and themiddle base in more detail. FIG. 11 is a second perspective viewillustrating the holder and the middle base in more detail.

Referring to FIGS. 10 and 11, FIG. 10 is a first perspective viewillustrating the holder 33 and the middle base 35 in more detail, and asecond perspective view of the holder 33 and the middle base 35illustrated in FIG. 11 illustrates the holder 33 and the middle base 35of FIG. 10 viewed from the opposite side (180 degrees).

The holder 33 includes the insertion hole into which the liquid lensunit 40 is inserted. The first perspective view illustrates a secondopening 97 included in the insertion hole, and the second perspectiveview illustrates a first opening 100 included in the insertion hole. Thefirst opening 100 may face the second opening 97 in the directionperpendicular to the optical-axis direction. The holder 33 may include asecond side surface in which the second opening 97 is located, and afirst side surface in which the first opening 100 is located.

As illustrated in FIG. 9, the second opening 97 may be disposed so as tobe opened toward the second long side of the main board 39, and thefirst opening 100 may be disposed so as to be opened toward the firstlong side of the main board 39. In addition, the liquid lens 42 may alsohave a first side surface located at or along the first long side and asecond side surface located at or along the second long side.

Thus, the first bending portion 64 of the common electrode connectionsubstrate 44 may be disposed at the position corresponding to the centerof the first side surface of the liquid lens 42, and the second bendingportion 61 of the individual electrode connection substrate 41 may bedisposed at the position corresponding to the center of the second sidesurface of the liquid lens 42.

In addition, the first lens unit 32 and the second lens unit 34 may bedisposed in the holder 33, and the liquid lens 42 may be disposedbetween the first lens unit 32 and the second lens unit 34 so that atleast a portion thereof may be disposed in the first opening 100 and thesecond opening 97 in the holder 33.

The liquid lens 42 may be inserted through at least one of the firstopening 100 or the second opening 97, and a portion of the liquid lens42 may protrude to the side surface of the holder 33. In addition, aportion of the liquid lens unit 40 including the liquid lens 42 mayprotrude to the side surface of the holder 33 through one of the firstopening or the second opening. In an embodiment, the spacer 43 of theliquid lens unit 40, which surrounds the side surface of the liquid lens42, may protrude outward from the holder 33 through one of the firstopening or the second opening.

To allow the liquid lens 42 to be inserted through at least one of thefirst opening 100 or the second opening 97, the center thickness of theliquid lens 42 may be smaller than the size of the first opening 100 orthe second opening 97 in the optical-axis direction.

As illustrated in FIG. 9, a virtual plane that passes through the firstopening 100 and the second opening 97 may not overlap a plurality ofcircuit elements 51.

The holder 33 and the middle base 35 may be coupled to each other uponthe implementation of first alignment and may be moved by a jig.

The holder 33 may be manufactured via an injection-molding process.Since the inner region of a second through-hole 96 in the holder 33 iscylindrical, the exterior of the second through-hole may be manufacturedto have a cylindrical shape in order to increase the yield of theinjection-molding process. In addition, a protruding portion 95 aroundthe insertion hole, which supports the liquid lens unit 40, needs tohave a minimum thickness D4 in order to reduce the thickness of theentire camera module 10-1. The insertion hole may include an upperplate, a lower plate facing the upper plate, and a first sidewall and asecond sidewall, which interconnect the upper plate and the lower plate.The protruding portion 95 means the outer rim of the lower plate.

Thus, the protruding portion 95 may inevitably have the minimumthickness D4. When the middle base 35 is not coupled to the holder 33,the jig needs to grip the protruding portion 95 upon the implementationof first alignment. However, because the protruding portion 95 has anextremely small thickness D4, the jig may have difficulty in grippingthe holder 33, and the holder 33 may be deviated depending on thedirection or angle of movement of the jig, which makes normalimplementation of first alignment impossible. In addition, sincemanufacturing tolerances may be increased as the thickness of the ribsof the holder 33 is increased, it is desirable to reduce the thicknessof the ribs constituting the holder 33. Since the jig may havedifficulty in gripping in the direction in which the insertion hole isdisposed when the thickness of the ribs constituting the holder 33 isreduced, the middle base 35 may be added so as to be coupled to theholder 33 so that the jig may easily perform alignment of the holder 33by supporting the middle base 35. It is noted that the middle base 35may be omitted. The middle base 35 according to the embodiment mayinclude an accommodating hole 98, which may accommodate the secondthrough-hole 96 therein (i.e. into which a portion of the holder 33 isinserted), and a recessed portion 99 to which an adhesive (e.g. epoxy)may be applied. In addition, the outer shape of the middle base 35 maycorrespond to the lower shape of the insertion hole in the holder 33,and the outer diameter of the middle base 35 may be equal to or greaterthan the distance between opposite protruding portions 95 around theinsertion hole. In other words, the length of the middle base 35 may begreater than the length of the holder 33 in the direction from the firstopening 100 to the second opening 97.

In addition, the thickness D5 of the middle base 35 may be greater thanthe thickness D4 of the protruding portion 95, but may be smaller thanthe length of the second through-hole. The material of the middle base35 may be liquid crystal polymer that is resistant to heat, but thescope of the disclosure is not limited thereto.

As in the camera module 10-1 according to the embodiment, when firstalignment is performed in the state in which the middle base 35 iscoupled to the holder 33, the jig may grip the middle base 35, ratherthan the protruding portion 95. Thus, because the middle base 35 has athickness D5 sufficient to be stably gripped by the jig, gripping may bestably performed so that the holder 33 does not shake regardless of thedirection or angle of movement of the jig, whereby first alignment maybe performed normally. When there is no middle base 35, the jig maysupport the side surface of the holder 33.

FIG. 12 is a view for explaining an embodiment of the common electrodeconnection substrate in more detail.

Referring to FIG. 12, the common electrode connection substrate 44,which electrically connects a common electrode of the liquid lens unit40 to the main board 39, may be implemented as a single metal substrate.

The common electrode connection substrate 44 may be implemented as ametal plate, which includes a metal insulation layer 110 disposed on anarea excluding a first pad 120, which is exposed at a positioncorresponding to an exposed pad at a position corresponding to a commonelectrode of the liquid lens 42, a second pad 130, which is exposed at aposition corresponding to the common electrode pad of the main board 39,and the groove 45. The first pad 120 and the second pad 130 mayrespectively be an upper terminal and a lower terminal.

Here, the metal insulation layer 110 may be divided into a first metalinsulation layer (the area at the right side of the groove 45), whichcorresponds to the outwardly exposed area of the liquid lens unit 40coupled to the common electrode connection substrate 44, and a secondmetal insulation layer (the area at the left side of the groove 45),which corresponds to the area of the liquid lens unit 40 coupled to thecommon electrode connection substrate 44, which is located below theliquid lens 42. The first metal insulation layer may be disposed on thearea that faces the inner side surface of the first cover 31, and thesecond metal insulation layer may be disposed so as to extend to thearea located below the liquid lens 42. The first metal insulation layerand the second metal insulation layer may have different operations andeffects.

The metal insulation layer 110 may be disposed on the top of a singlemetal substrate, which is in electrical conduction via a single node, bycoating, plating, or deposition, and may include Parylene C. The commonelectrode connection substrate 44 may bend toward the common electrodepad of the main board 39 in the first bending area 64, which is guidedby the groove 45, thereby being electrically connected to the main board39. When the first cover 31 is mounted, the first cover 31 may be incontact with the individual electrode connection substrate 41 and thecommon electrode connection substrate 44. At this time, the first cover31 may be formed of a conductive metal in consideration of the weightand strength thereof. When the first cover 31 is brought into contactwith the individual electrode connection substrate 41 and the commonelectrode connection substrate 44, short-circuiting may occur betweenthe individual electrode and the common electrode of the liquid lens 42.Due to this short-circuiting, the driving of the liquid lens 42 may betemporarily or continuously impossible.

However, the common electrode connection substrate 44 according to theembodiment may include the metal insulation layer 110 (moreparticularly, the first metal insulation layer) disposed on the areaexcluding the second pad 130 for connection with the main board 39,thereby inhibiting short-circuiting due to the first cover 31.

FIG. 13 is a view illustrating the cross section of a portion of theliquid lens unit including the common electrode connection substratehaving the structure illustrated in FIG. 12.

Referring to FIG. 13, the liquid lens unit 40 may have a structure inwhich the individual electrode connection substrate 41, the liquid lens42 coupled to or surrounded by the spacer 43, and the common electrodeconnection substrate 44 are stacked one above another. The spacer 43 mayprotrude outward from the individual electrode connection substrate 41and the common electrode connection substrate 44 so as to be broughtinto contact with a gripper during an active alignment process.

Here, the common electrode connection substrate 44 may include the metalinsulation layer 110 (more particularly, the second metal insulationlayer), which corresponds to the area disposed below the liquid lens 42.Since the metal insulation layer 110 is disposed on the area excludingthe first pad 120, which is exposed at a position corresponding to theexposed pad at a position corresponding to the common electrode of theliquid lens 42, a gap 150 may be formed between the exposed pad at aposition corresponding to the common electrode of the liquid lens 42 andthe first pad 120.

The exposed pad at the position corresponding to the common electrode ofthe liquid lens 42 and the first pad 120 may be electrically connectedand bonded to each other via a conductive adhesive (e.g. Ag epoxy).Since the gap 150 is formed therebetween, it is possible to inhibit theconductive adhesive from leaking outward from the liquid lens unit 40and to inhibit short-circuiting with another terminal (e.g. theindividual electrode).

The gap 150 may provide a height difference equal to the thickness ofthe metal insulation layer 110, and for example, the thickness of themetal insulation layer 110 may range from 20 μm to 40 μm.

The above-described liquid lens may be included in the camera module.The camera module may include a lens assembly, which includes a liquidlens mounted in a housing and at least one solid lens disposed on thefront surface (or, top surface) or the rear surface (or, bottom surface)of the liquid lens, an image sensor, which converts an optical signaltransferred from the lens assembly to an electric signal, and a controlcircuit, which supplies a drive voltage to the liquid lens.

Although some embodiments have been described above, various otherembodiments are possible. These embodiments may be combined in variousforms so long as the technical ideas of the embodiments are notincompatible, and thus new embodiments may be realized therefrom.

For example, an optical device including the camera module, whichincludes the liquid lens described above, may be implemented. Here, theoptical device may include a device that may process or analyze opticalsignals. Examples of the optical device may include camera/videodevices, telescopic devices, microscopic devices, an interferometer, aphotometer, a polarimeter, a spectrometer, a reflectometer, anauto-collimator, and a lens-meter, and the embodiments may be applied tooptical devices that may include the liquid lens. In addition, theoptical device may be implemented in a portable device such as a smartphone, a laptop computer, or a tablet computer. Such an optical devicemay include a camera module, a display unit configured to output animage, and a body housing in which the camera module and the displayunit are mounted. A communication module, which may communicate withother devices, may be mounted in the body housing of the optical device,and the optical device may further include a memory unit capable ofstoring data.

It will be apparent to those skilled in the art that the disclosure maybe embodied into other particular forms within a range not deviatingfrom the scope and essential features of the disclosure. Thus, the abovedetailed description should not be construed as being limitative in allterms, but should be considered as being illustrative. The scope of thedisclosure should be determined by the rational analysis of theaccompanying claims, and all changes within the equivalent range of thedisclosure are included in the scope of the disclosure.

MODE FOR INVENTION

As described above, a related description has sufficiently beendiscussed in the above “Best Mode” for implementation of theembodiments.

INDUSTRIAL APPLICABILITY

A camera module and an optical device, which include a liquid lensaccording to embodiments, may be used in camera/video devices,telescopic devices, microscopic devices, an interferometer, aphotometer, a polarimeter, a spectrometer, a reflectometer, anauto-collimator, a lens-meter, a smart phone, a laptop computer, or atablet computer.

1. A camera module comprising: a board having a plurality of circuitelements and an image sensor; a holder disposed on the board andcomprising a side wall having a hole; a first lens unit disposed in theholder; and a focus adjustable lens unit disposed in the holder, atleast a portion of the focus adjustable lens unit disposed in the hole,wherein the focus adjustable lens unit is disposed on the first lensunit, wherein the board comprises a first long side, a second long sideopposite the first long side, and a short side connecting the first longside and the second long side, and wherein the hole is opened toward thefirst long side of the board.
 2. The camera module according to claim 1,comprising: a second lens unit disposed in the holder, wherein the focusadjustable lens unit is disposed between the first lens unit and thesecond lens unit.
 3. The camera module according to claim 1, wherein thehole comprises a first hole and a second hole, and wherein the secondhole faces the first hole in a first direction perpendicular to anoptical axis direction.
 4. The camera module according to claim 3,wherein the focus adjustable lens unit is disposed between the firsthole and the second hole.
 5. The camera module according to claim 3,wherein the side wall comprises a first side wall and a second side walldisposed opposite to the first side wall, wherein the first side wallhas the first hole, and wherein the second side wall has the secondhole.
 6. The camera module according to claim 4, wherein a part of thefocus adjustable lens unit is disposed in at least one of the first holeand the second hole.
 7. The camera module according to claim 6, whereina part of the focus adjustable lens unit protrudes outward from theholder through at least one of the first hole and the second hole. 8.The camera module according to claim 1, wherein the focus adjustablelens unit comprises a first material and a second material differentfrom the first material.
 9. The camera module according to claim 8,wherein the first material comprises water and the second materialcomprises oil.
 10. The camera module according to claim 3, wherein thefirst hole is opened toward the first long side of the board, andwherein the second hole is opened toward the second long side of theboard.
 11. The camera module according to claim 5, wherein the focusadjustable lens unit is inserted through the first hole and the secondhole, wherein a first portion of the focus adjustable lens unitprotrudes out from the first side wall, and wherein a second portion ofthe focus adjustable lens unit protrudes out from the second side wall.12. The camera module according to claim 1, wherein the focus adjustablelens unit has a center thickness smaller than a size of the firstopening in the holder, in a second direction parallel to the opticalaxis of the focus adjustable lens unit.
 13. The camera module accordingto claim 1, wherein the circuit elements do not overlap a virtual plane,which passes through the first opening and is parallel to an uppersurface of the board, in a second direction parallel to the optical axisof the focus adjustable lens unit.
 14. The camera module according toclaim 1, wherein the focus adjustable lens unit comprises a focusadjustable lens, and wherein the focus adjustable lens comprises: afirst plate comprising a cavity in which a conductive liquid and anon-conductive liquid are disposed; an individual electrode disposed onone surface of the first plate; and a common electrode disposed onanother surface of the first plate.
 15. The camera module according toclaim 8, wherein the focus adjustable lens unit comprises: a firstconnection substrate disposed on the focus adjustable lens andconfigured to electrically connect the common electrode and the board; asecond connection substrate disposed on the focus adjustable lens andconfigured to electrically connect the individual electrode and theboard; and a first side surface located at the first long side of theboard and a second side surface located at the second long side of theboard, and wherein the first connection substrate comprises a firstbending portion, which is connected to the common electrode, bendstoward the board, and is disposed at a first position corresponding to acenter of the first side surface of the focus adjustable lens unit. 16.The camera module according to claim 9, wherein the second connectionsubstrate comprises a second bending portion, which is connected to theindividual electrode, bends toward the board, and is disposed at aposition corresponding to a center of the second side surface of thefocus adjustable lens unit.
 17. The camera module according to claim 10,comprising a first pad portion configured to be electrically connectedto the first connection substrate, wherein the first pad portion isdisposed on the board at a second position corresponding to the centerof the first side surface of the focus adjustable lens unit and extendsaway from the circuit elements.
 18. The camera module according to claim9, comprising an insulation material and a cover covering an uppersurface and a side surface of the holder, wherein the first connectionsubstrate is a metal plate, wherein the metal plate comprises: a lowerterminal configured to be electrically connected to the board; and anupper terminal configured to be electrically connected to the focusadjustable lens, and wherein the insulation material is disposed on themetal plate in an area that faces an inner side surface of the cover.19. A camera module, comprising: a board having a plurality of circuitelements and an image sensor; a holder disposed on the board andcomprising a side wall having a hole; a first lens unit disposed in theholder; and a focus adjustable lens unit disposed on the first lensunit, wherein the focus adjustable lens unit is inserted through thehole and overlapped with the hole in a direction perpendicular to anoptical axis. wherein the board comprises a first long side, a secondlong side opposite the first long side, and a short side connecting thefirst long side and the second long side, and wherein the hole is openedtoward the first long side of the board.
 20. A camera module,comprising: a board having a plurality of circuit elements and an imagesensor; a holder disposed on the board and comprising a side wall havinga hole; a first lens unit disposed in the holder; a second lens unitdisposed in the holder; an interface variable lens disposed between thefirst lens unit and the second lens unit; and a board disposed under theholder, a plurality of circuit elements and an image sensor beingdisposed on the board, wherein the interface variable lens comprises afirst material, a second material on the first material and an interfacebetween the first material and the second material, wherein a part ofthe interface variable lens is disposed in the hole, and wherein theboard comprises a first long side, a second long side opposite the firstlong side, and a short side connecting the first long side and thesecond long side, and wherein the hole is opened toward the first longside of the board.